Display brightness issue, dimmed picture

Hi, I’m a fairly new NixOS user, so I’d really appreciate some help troubleshooting this issue. Right after powering on, my desktop computer shows a very bright manufacturer’s logo, but as soon as the first boot messages appear, the screen gets noticeably darker—even though I’ve set the monitor brightness to 100%. This is also evident, for example, when switching modes or resolutions, where the OSD elements (especially whites) are clearly brighter than what the system itself generates. What can I do to fix this, and what information should I provide to help diagnose it? I’m running Gnome 49 (Wayland), and my graphics card is an RTX 5070 Ti (stable drivers+open kernel modules). On KDE Plasma, the desktop looks a bit better and brighter overall, but the boot fonts are still dimmed. With Gnome, it feels like even the desktop is noticeably darker than it could be.

25.11.4657.1cd347bf3355 (Xantusia)
6.18.6-zen1

lsmod | grep -i nvidia
nvidia_uvm 3973120 16
nvidia_drm 143360 126
nvidia_modeset 2281472 14 nvidia_drm
video 81920 2 amdgpu,nvidia_modeset
drm_ttm_helper 20480 3 amdgpu,nvidia_drm
nvidia 15929344 601 nvidia_uvm,nvidia_modeset
ecc 49152 2 ecdh_generic,nvidia

gnome-randr
supports-mirroring: true
layout-mode: logical
supports-changing-layout-mode: true
global-scale-required: false

logical monitor 0:
x: 0, y: 0, scale: 1.6666666269302368, rotation: normal, primary: yes
associated physical monitors:
DP-1 SAM LC34G55T HNTY906728

1 Like

hey i dunno if that is related but have you tried enablling performance mode in nixos and also maybe you should check if that isn’t some setting in bios that like “preservers” your display health you know. so yeah first of all check every power saving feature including in bios
then take a look in the entire dmesg log if there is anything useful like warning about gpu/lcd you know